Italian composer and singer, born in Arezzor. As a boy Pietro sang in the choir at Arezzo Cathedral (ca. 1630) and at S. Maria della Pieve (1635-37). After joining the Franciscan order (in 1637, at which time he assumed the name Antonio) he was sent to Florence (S. Croce, ca. 1638-40), then back to Arezzo (ca. 1640-43). Apparently he did study in Rome, although his purported study with Carissimi and Antonio Maria Abbatini has not been fully documented. From 1644 Cesti was apparently organist both at the Volterra Cathedral and at S. Croce in Florence; he became magister musices at Volterra in 1645. Around 1647 he was ordained to the priesthood. During the late 1640s he also served members of the Medici family, including Cardinal Gian Carlo. His first opera, Orontea (libretto G. Cicognini), performed in Venice in 1649, was a sensational success; it was followed by a number of other successes, including Il Cesare amante(1651). Meanwhile Cesti was also gaining favor on the stage as a tenor.
In 1652 he was appointed Chor-Kapellmeister at the Innsbruck court of Archbishop Ferdinand Karl, a position he held until 1665. In 1658 he sang at the papal chapel, but upon achieving release from his monastic orders the following year he promptly returned to Innsbruck. (Some have suggested that he sought the papal appointment expressly in order to gain favor to secure this release.) When the archbishop's court disbanded in 1665, Cesti followed it to Vienna, where his Il Tito was staged in 1666. The culmination of his career as an opera composer was in his last opera for Vienna, Il pomo d'oro (1668), a pinnacle of Baroque opera on the gigantic scale. Cesti reportedly died traveling to Florence the following year. Other known works include the operas La Dori (Innsbruck, 1657), Nettunno e Flora festeggianti (1666), and La Semirami (1667); over sixty cantatas, including Era la notte e muto, Quante volte, and Vaghi fiori.